This invention relates generally to a power screwdriver and more particularly to a portable-type screwdriver where fasteners are automatically fed to a driving position.
There are a number of tools adapted to sequentially drive threaded fasteners wherein the fasteners are automatically fed to a position beneath a driving spindle in readiness for the next operating stroke. However, most of these devices are designed for stationary operation where the work to be fastened is brought to the driver. These devices are clearly unacceptable for use as portable power tools. Efforts to provide a portable screwdriver capable of automatically feeding fasteners to the nosepiece have primarily been concerned with developing an integrated driving unit wherein the driving energy is also used to positively feed fasteners to their operative positions.
It is, accordingly, an object of this invention to provide a driving tool which enables a workman to fasten a screw to a workpiece while the workman remains in a standing or substantially standing position.
A further object of the invention is the provision of an attachment to a conventional electric powered rotary screwdriver, thereby facilitating its use on a construction site.
Still a further object of the invention is the provision of a driving attachment incorporating a gravity feed tube.
An advantage of the invention is a novel feed control device which insures that only a single fastener is fed to the nosepiece for each driving stroke.
In general, these objects are obtained by a Y-shaped attachment including a driving spindle located in one section of the Y and a feed tube comprising the other section of the Y. The driving spindle is adapted for operative connection with a fastener driving tool at an upper tubular portion of the attachment. The upper tubular portion and driving spindle are further mounted for reciprocatory and telescopic movement downwardly relative to a lower tubular portion which is integrally connected to a nosepiece. The movement of the upper tube activates an escapement device which feeds fasteners from the feed tube to the nosepiece with the feeding being accomplished during the return, upward stroke of the spindle.